ABSTRACT
Physical reality is finite. Every set of physical objects, every sequence of physical events, has a determinate number of members, just as every individual physical object is of determinate size and every physical process has a determinate duration – and infinity is not a determinate number or amount. Movements, changes of temperature and other physical processes can be thought of either as causes or as effects. A natural law tells how things must behave as a matter of physical necessity if they exist; no law can tell that things will exist or that there will always be behaviour for it to apply to. In that respect laws of physical nature are like the laws of human societies. The laws of England tell how the English must behave as a matter of social obligation. Parliament is capable of any tyranny, and a megalomaniac government might force through laws ordering Englishmen to have children and forbidding them to emigrate.
